Double throw switch



Jan. 14, 1941. B. E. SHAW DOUBLE THROW SWITCH Filed Hay l, 1939 PatentedJan. 14, 1941 Y UNITED STATES PATENT! ori-ica DOUBLE THROW SWITCH BurtonE. Shaw, Bristol, Ind., assigner to Penn Electric Switch Co., Goshen,Ind., a corpora tion o! Iowa l Application May 1, 1939, senat No.271,122 17 claims (ci. 20o-e7) An object of my present invention is toprodevice, whereby the objects contemplated are atvide a switchstructure including a switch arm tained, as hereinafter more fully setforth, pointpivotally mounted so that it can be rocked one ed out in myclaims, and illustrated in the accomway for opening one set of contactsand the other panying drawing, inwhich: way for opening another set ofcontacts and clos- Figure 1 is a plan view of a double throw ing thefirst set, permanent magnets being assoswitch embodying my invention,the cover being ciated with each end of the switch arm and such omittedtherefrom in order to show internal ends having armatures carriedthereby for costructural details, this view being about twice actionwith the permanent' magnets to, provide actual size.

snap action for both sets of contacts. Figure 2 is a sectional view onthe line 2-2 of 10 Another object is to provide a compact switch Figure1 showing the cover in position. unit adaptable for carryingcomparatively heavy Figure 3 is a sectional view on the line 3-3 ofcurrent loads, the switch being so constructed and Figure 2. thecomponent parts thereof being so designed Figure 4 is a side elevationof my switch strucand arranged as to provide a minimum number ture withthe cover removed and the lower` por- 15 of parts and a very compactarrangement thereof tion of the base broken away. whereby a switchstructure of large capacity may Figure 5 is a sectional view on the line5-5 of be made comparatively small in size. Figure 2. More particularlyit is an object of my inven- Figure 6 is a perspective view of a bracketused tion to provide a switch unit including a base and in my switchstructure. :20l

a cover therefor with three terminals mounted Figure 7 is a sectionalview on the line l-l of in the base and switch mechanism mounted with-Figure 2. in the cover and comprising a stationary contact Figure 8 is asectional view on the line 8 8 of mounted on each terminal with a pairof leaf Figure 2; and

springs carrying contacts which normally en- Figure 9 is a perspectiveview of a spring used 25 gage the stationary contacts, a centrallypivoted in connection with the armature of my structure switch arm beingprovided for disengaging the for effecting adjusting ot the armature andthereleaf spring contacts from the stationary contacts by thedifferential of operation of the switch and an operating pin for theswitch arm extendstructure.

ing through the cover. On the accompanying drawing I have used the 30 Afurther object is to provide opposite ends of reference character B toindicate a base and C a the switch arm with armatures and to providecover therefor. 'I'he cover C is provided with ina magnet for eacharmature, the armatures beternal bosses I0 through which screws I2extend, ing adjustable in a novel manner relative to the the headsthereof being counter-sunk in the base switch arm for changing thedifferential of op-V B and the shanks of the screws extending beyond 35eration of either set of switch contacts. Y the cover C as in Figure 2whereby they may be A further object is to provide means to retainthreaded into any suitable type of support S. the magnets in positionwhich consists of brack- In Figure' 6 I illustrate a bracket A having aets mounted on terminals of the switch and base part I3 and perforatedears I4 and I5. The 40 which also serve as stops for the ends of thebracket A is secured to the base B by a terminal 40 switch arm in itsdiilferent positions. sleeve I6. The upper end of the sleeve I6 hasStill a further object is to provide means for a square head Il whileits lower end is rivetedoperating the switch arm including a stationaryover a washer I8. At one side of the portion I3 spring for one end tonormally urge the switch v of the bracket A, a ange I9 is provided whicharm in one direction and a movable pin for the rests against a shoulder20 of the base B to pre- 45 other and having a spring connection withsuch vent turning of the bracket A and sleeve I6. A other end. terminalscrew 2l is threaded into the lower end Still another object is toprovide a means for oi'. th terminal sleeve I6. mounting the switch armand the leaf springs I provide other terminal sleeves IE and I6b thatcarry the contacts on a single bracket which having similar washers I8aand I8b and terminal 50 is retained in assembled position by another ofscrews 2Ia and 2lb. `The sleeves Ilia and IBb are the terminals of theswitch. adjacent sockets 22 and 22a formed in the base B With these andother objects in view, my into receive permanent horseshoe magnets 23and vention consists in the construction, arrange- 23a. The magnets 23and 23a are retained in the u ment and combination of the various partsof my sockets 22 and 22a by brackets 24 and 24a formed 55 The bracket Ais provided with a. pair of lugsy 26 and 26a, which are screw threadedto receive screws 21 and 21a respectively. The screw 21 serves to anchorone end of a leaf spring 28, while the screw 21a similarly serves toanchor one end of a leaf spring 28a. Contacts 29 and 29a are carried bythe leaf springs 28 and 28a respectively for coaction with the contacts25a and 25 respectively. 'I'he springs 28 and 28a are, under tension tonormally engage the contacts 29 and 29a with the contacts 25a and 25 andthe tension may be varied as desired byv bending the lugs 28 and`28a.

I provide a switch arm 30 having a pair of perforated ears 3| adapted toreceive a pivot pin 32. The pivot pin 32 is supported in the pivot earsI4 and I5. Opposite ends of the switch arm 30 are bent downwardly asindicated at 32 and 32a to engage the brackets 24 and 24a, whereas theone bracket serves as a stop for the arm in one of its positions and theother bracket serves as a stop therefor in its other position. Theportions 32 and 32a of the switch arm 30 are perforated as at 33 and 33ato receive the ends of the leafl springs 28a and 28 respectively wherebyoperation of the switch arm may serve to actuate the leaf springs andthereby control the circuits through the contact mechanism of theswitch.

For the magnet 23, an armature 34, is provided and for the magnet 23a Iprovide a similar armature 34a. The armatures are mounted on the switcharm'30 adjacent the ends thereof by screws 35 and 35a. Interposedbetween the heads of the screws and the switch arm are leaf springs 36and 36a which are of the shape shown in Figure 9. These springs serve tospace the armature from the switch arm as at the right side of Figure 2when the screw is loosened thus keeping the armature substantiallyparallel to the switch arm in the different positions of adjustment andthereby always at the proper angle relative to the pole faces of themagnets. The springs 36 and 36a, it will be noted, have upwardlyinclined fingers and these are reduced substantially equally ininclination as the screw is tightened. To prevent rotation of thearmatures 34 and 34a they are provided with lugs 42 and 42a engagingopposite sides of the switch arm 30.

With the portions 32 and 32a of the switch arm 30 acting as stops, thearmatures, however, are prevented from actual contact with the magnetsas can be seen in Figure 4, but the differential of operation of eitherset of contacts of the switch may be varied by loosening the screws 35or 35a to decrease the differential or tightening them to increase thedifferential as the magnetic attraction is in inverse squared proportionto the distance of the armature from the magnet when the armature is instopped position as at the left side of Figures 2 and 4.

One end of the switch arm 30 is provided with a projection 31 with whicha spring 38 coacts, the spring being mounted on a projection 39 from thetop of the cover C. The tension of the spring 38 is such that itnormally tends to separate the contacts 25a and'29 and permit thecontacts 25a and 29 to engage.

For operating the switch against the constraint of the spring 38,-1provide a spring 38a. It is interposed between a projection 31a of theswitch arm 30 and an operating pin 40. The pin 40 is slidable in a boss4| of the cover C and may be engaged by any suitable operatingmechanism, 'such as a bellows, bimetaliic element or the like.

'I'he foregoing described switch is very compact in arrangement, yet iscapable of carrying relatively heavy currents since snap action isprovided by the magnet and-armature arrangement. The compactness of thestructure is due to several features of design, among which may be men-Itioned:

l. The bracket A which serves as a pivotal mounting for the switch arm`30 and has an anchorage means and current conducting means for theswitch blades 28 and 28a;

2. The terminal sleeve I8, ||ia and |6b serve to secure the brackets A,24 land 24a in position and at the same time serve as receptors for theterminal screws 2|, 2|a and 2lb;

3. The brackets 24 and 24a serve both as a means to retain the magnets23 and 23a in position and as stops for the ends 32 and 32a of the 4.The spring 38 is under tension to normally swing the switch arm 30 inone direction, whereas the normal tendency is for the switch arm to stayat either position due to the effect of the magnets on the armatures,the operating pin 40 then serving through the spring 38a to swing theswitch arm to its other position when the pressure against the pin issufcient tc load the spring 38a until its tension overcomes the tensionof the spring 38 plus the pull of the magnet 33 on the armature 34.

When the pin 40 is later permitted to move outwardly in the boss 4|, apoint will be reached before the position of Figure 2 is assumed wherethe tension of the spring 38 will overcome the pull of the magnet 23a onthe armature 34a plus the tension of the spring 38a and the switch willreturn to the position shown in Figure 2.

Some changes may be made in the construction and arrangement of theparts of my device without departing from the real spirit and purpose ofmy invention, and it is my intention to cover by my claims, any modifiedforms of structure or use of mechanical equivalents, which may bereasonably included within their scope.

I claim as my invention:

1. In a double throw switch, a base, a switch arm centrally pivotedthereon, an armature carriediby eachend of said switch arm, a magnet foreach armature to impart snap action to the switch arm when moved ineither direction, a pair of leaf springs between said base and saidswitch arm, overlapping each other and each at one end extending beyondthe other, said leaf springs each having its other end anchored, acontact carried by each of said first ends of said leaf springs, astationary contact on said base for each leaf spring contact, said leafspring contacts being normally engaged with said stationary contacts,said switch arm cooperating with said leaf springs to disengage one setof contacts from each other when the switch arm is moved in onedirection and to disengage the other set of contacts from each otherwhen the switch arm is moved in the other direction, means biasing saidswitch arm to one of said positions and an actuator for moving it to theother of said positions.

2. In a double throw switch, a base, a switch arm pivoted intermediateits ends thereon, an armature carried by each end of said switch arm, amagnet for each armature to impart snap action' to the switch arm whenmoved in either direction, a pair of leaf springs between said base and,said switch arm and overlapping each other,

said leaf springs each having one of its ends anchored, a contactcarried by the other end of I each leaf spring, a stationary contact onsaid base for each leaf spring contact, said leaf spring contacts beingnormally engaged with said stationary contacts, said switch armcooperating with said leaf springs to disengage one set of contacts fromeach other when the switch arm is movedin one directionand to disengagethe other set of contacts from each other when the switch arm ismoved inthe other direction and an actuator for effecting movement of saidswitch arm to its different positions. i

3. In a double throw switch, a base, a bracket thereon having threesupports at different distances from said base, a switch arm pivoted toone of said supports, a pair of armatures carried by said switch arm, amagnet for each armature to impart snap action to the switch arm whenmoved in either direction, a pair of leaf springseach having one of itsends anchored relative to one of the remaining supports with the springsparallel to said base, and a portion of one' spring overlapping aportion of the other, a contact car'- ried by the other end of each ofsaid leaf springs beyond said overlapping portions thereof and asstationary contact for each leaf spring contact, said leaf springcontacts being normally engaged therewith, said switch arm cooperatingwith said leaf springs to disengage one set of contacts from each otherwhen the switch arm is moved in one direction and to disengage the otherset of contacts from each other when the switch arm is moved in theother direction.

4. In a switch structure, a movable switch arm, a pair of oppositelydirected leaf springs each having one of its ends anchored, the portionsof 40 said leaf springs adjacent Said anchored ends overlapping eachother and contacts carried by the other ends of said leaf springs beyondsaid overlapped anchored ends thereof, a stationary contact for eachleaf spring contact, said switch 45 arm cooperating with said leafsprings to effect operation of said contacts with relation to each otherwhen the switch arm is moved in opposite directions, means biasing saidarm to one of its opposite positions and an actuator for moving 50 it tothe other of its opposite positions.

5. In a switch structure, a base, three terminals thereon, a bracketmounted on said base by the center terminal, a switch arm pivotedintermediate its ends to said bracket, said bracket 55 having a pair oflugs, a pair of leaf springs, each 'having one end anchored to one ofsaid lugs, said leaf springs extending toward and past each other andone of them being located between the other one and the base, contactscarried by said leaf springs, the second and third terminals havingstationary contacts normally engaged by said leaf spring contacts, saidswitch arm having means to pick up one of said leaf springs when theswitch arm is rocked in one direction and to pick up the other leafspring when it is rocked in the other direction and means to impart snapaction to said switch arm when moved to either Vof said two positions.

6. In a'.` switch structure, a base, three terminals thereon, a bracketmounted on said base by cooperation of the center one of said terminalstherewith, a switch arm pivoted to said bracket, f

a pair of leaf springs, each having one end anchored to said bracket,said leaf springs extending toward and past each other, contacts carriedby said leaf springs, the remaining terminals having stationary contactsnormally engaged by said leaf spring contacts,-said switch arm havingmeans to pick up one of said leaf springs when the switch arm is rockedin one direction and to pick up the other leaf spring when it vls rocked.in the other direction and means to impart snap action to said switcharm when moved to either of said two positions.

7. In a switch structure, a base,` three substantially aligned terminalsthereon, a bracket mounted on Said base by the center one of saidterminals, a switch arm pivoted intermediate its ends to said bracket, apair of reversely arranged leaf springs, each having one end anchored tosaid bracket with portions of said leaf springs the points of anchoragearranged in overlapping relation, and contacts carried by said leafsprings, the second and third terminals having stationary contactsnormally engaged by said leaf spring contacts, said switch arm havingmeans alternately coacting with said leaf springs to separate theircontacts from said stationary contacts when the switch arm is rocked inopposite directions.

8. In a switch structure, a base, a bracket mounted on said base andhaving a pair of lugs, a pair of leaf springs, each having one endanchored to one of said lugs, said leaf springs extending toward andpast each other and one of them being located between the other end andsaid base, contacts carried by said leaf springs, stationary contacts onsaid base normally engaged by said leaf spring contacts, a switch armpivoted on said base,v said switch arm having means to pick up one ofsaid leaf springs when the switch arm is rocked in one direction and topick up the other leaf spring when it is rocked in the other directionand means to impart movement to said switch arm to effect movementthereof to either of said two positions.

9. In a switch structure, a base, three terminals thereon, a bracketmounted on said base by the center terminal, a switch arm pivotedintermediate its ends to said bracket, second and third brackets on theend terminals, a magnet at each end of said base and coacting with theends of said switch arm to produce snap action thereof when the arm ismoved in either direction, said base having sockets receiving saidmagnets, said brackets retaining said magnets in said sockets resilientmeans urging said switch arm in one direction and an actuating pin formoving it in the other direction.

10. In a switch structure, a base, a bracket mounted on said base, aswitch arm pivoted intermediate its ends to said bracket, second andthird brackets on said base, a pair of U-shaped magnets coacting withsaid switch arm to produce snap action thereof when moved in eitherdirection, said base having sockets adjacent said second and thirdbrackets receiving said magnets at their crosspieces said second andthird brackets having iingerlike extensions located between the poles ofsaid magnets and thereby retaining said magnets in said sockets andmeans for imparting movement to said switch arm.

11. In a switch structure, a base, three terminals thereon, a bracketmounted on said base by said center terminal, a switch arm pivoted tosaid bracket, second and third brackets on the end terminals, a magnetend coacting with each end of said switch arm to produce snap actionthereof when moved in either direction, said last two brackets retainingsaid magnets assembled on said base, means urging said switch arm tomove in one direction and an actuating, element for moving it in theother direction.

12. In a switch structure, a base, magnet sockets therein, a bracketmounted on said base, a switch arm pivoted to said bracket, second andthird brackets on said base,'a pair of magnets mounted in said socketsand coasting with said switch arm to produce snap action thereof whenthe arm is moved in either direction, said second and third bracketsretaining said magnets in said sockets, contacts carried by said secondand third brackets and cooperating contacts controlled by said switcharm.

13. In a switch structure, a base, three terminals thereon, a bracketmounted on said base by the center terminal, a switch arm pivoted tosaid bracket, a magnet for each end of said switch arm, an armature oneach end of said switch arm, each of said armatures comprising a plateelement, a screw for mounting said plate element on the switch arm, lugmeans to prevent rotation of the armatures relative to the switch armwhen the screws are rotated, a spring between each arma'- ture and theswitch arm and comprising a relatively iiat central portion and upwardlyinclined fingers capable of substantially equal reduction in inclinationupon tightening oi said screw and an actuating element for moving saidswitch arm.

14. In a switch structure, a switch arm pivotally mounted, an armatureon said switch arm and comprising a'plate element, a screw for mountingsaid plate element on the switch arm, means to prevent rotation of thearmature relative to the switch arm when the screw is rotated, a leafspring between said armature and the switch arm and comprising arelatively fiat central portion and upwardly inclined fingers capable ofsubstantially equal reduction in inclination upon tightening of saidscrew and means for imparting pivotal movement to said switch arm.

15. In a switch structure of the character described, a base, a covertherefor, a switch arm having its central portion pivoted to said base,a spring carried by one end of said cover and engaging said switch armto normally throw the switch arm in one direction, an actuating pinslidably carried by the other end of said cover, a

spring interposed between said actuating pinand end of thereof,

the other end of said switch arm to swing the switch arm in the oppositedirection upon depression of said actuating pin a predetermineddistance, permanent magnets associated with each said switch arm toeifect` snap action the tension oi.' said nrst spring being sufficientto swing said switch arm to one position against the action oi' one of'said magnets and the second spring thereon, and a pair ofA Vcontactmechanims, one for opening a circuit when the switch arm is swung in onedirection and the other for opening a circuit when the switch arm isswung in the opposite direction.

16. In a switch structure, a pivotally mounted switch arm, a springengaging said switch arm to normally swing it in one direction,actuating means, a second spring interposed between said actuating meansand said switch arm, said second spring being operative to swing theswitch arm in the opposite direction upon movement of said actuatingmeans to a predetermined position, magnets associated with said switcharm to eect snap action thereof, the tension of said ilrst spring beingsuiiicient to swing said switch arm to one position against the actionof one of said magnets and of said second spring thereon, and a pair ofcontact mechanisms, one for opening a circuit when the switch arm isswung in one direction and the other for opening a circuit when theswitch arm is swung in the opposite direction.

17. In a double throw switch, a base, a switch arm pivoted thereon andarranged substantially parallel thereto, means to impart snap action tosaid switch arm when moved in eitherdirection, a pair of leaf springsbetween said base and said switch arm and also arranged substantiallyparallel to said base, said leaf springs overlapping each other and eachat one end extending beyond the other, said leaf springs each having itsother end anchored, and a contact carried by each of said nrst ends, astationary contact on said base for each leaf spring contact, saidswitch arm cooperating with said leaf springs to engage and disengagetheir contacts with relation to said stationary contacts when the switcharm is moved in either direction and an actuator for said switch arm.

BURTON E. SHAW.

